function [x,y,s] = mask(a,idx,orient,vals)

x = cell(4,1);
y = cell(4,1);
s = cell(4,1);

x{1} = [-1 -1 1 1 -1];
y{1} = [-1 1 1 -1 -1];
s{1} = 'k';

x{2} = [-0.5 -0.5 -0.25 -0.25 -0.5];
y{2} = [0.4 0.15 0.15 0.4 0.4];
s{2} = 'b';

x{3} = [-0.05 -0.05 0.5];
y{3} = [-0.4 0.4 0.4];
s{3} = 'b';

x{4} = [-0.05 0.3];
y{4} = [0.05 0.05];
s{4} = 'b';
